Granted Patent
Utility
US 4,247,316 · App. 06/055,709
Gas separation filter device having a handle
Inventor:
William A. Putman
Patented Case
View Patent ↗
Granted: Jan 27, 1981
Filed: Jul 9, 1979
Inventor
William A. Putman
Assignee (at issue)
AMERICAN AIR FILTER COMPANY, INC.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.